Chemical product



Patented 10, 1936 PATENT OFFICE 'CHEDIICAL PRODUCT Frederick Baxter Downing, Carneys Point, N. J., and Richard Gesse Clarkson, Wilmington, Del., assignors to E. I. du Pont de Nemours & Com- P y, Wilmington,.Del., a corporation of Delaware No Drawing. Application May 24, 1932,

Serial No. 613,261

This invention relates to alkaline aqueous media of improved wetting, penetrating and dispersing powers, more particularly baths for the treatment of textile fibers, and a process for the production thereof.

It is an object of the invention to produce alkaline aqueous media characterized by improved wetting, penetrating anddispersing properties. Afurther object is the production of alkaline aqueo'us baths for the. treatment of textile materials. A still further object is to produce aqueous baths which are relatively concentrated -in alkaline'reacting substances and yet possess marked wetting, penetrating and dispersing characteristics. A more specific object is the production of relatively concentrated solutions ozlE alkali metal hydroxides which possess improved'wetting, penetrating and dispersing, powersandare especially well adapted for the treatment of cellulosic materials. Another object of v the invention is to produce'baths highlyefficient for the mercerization of cotton materials. A furtherv object is to produce baths which are efiicient to such an extent that unboiled or grey cotton may be mercerized directly by treatment therewith. A; still further object is the provision of'new and improved processes for producing products of the character above described. Other objects appear hereinafter.

These objects are accomplished according to the invention by adding or forming in strongly alkaline aqueous media a soluble salt of analiphatic carboxylic acid having at least five "and preferably not more than twelve carbon atoms. The resultant products possess highly desirable wetting, penetrating and dispersing properties and are particularly valuable in the treatment of textile materials.

The invention may be well illustrated by its 40 application to the mercerization' of cotton fibers,

fabrics and yarns. In the lmercerization process-as ordinarily conducted, the first step consists in cleansing the cotton by fboiling out,

generally by means of a relatively dilute alkaline solution, to remove the grease from the surface I of the fibers and permit the penetration of the alkaline liquid during the mercerization process proper. Unless'the cleansing is carried outwith great care so as to remove substantially all of the natural waxes and other water-repellant material, the mercerization isuneven and results in fibers, fabrics and yarns which cannot be dyed evenly.

We have found that the soluble salts of the shorter chain fattyacids, i. e., those containing (cu-2o) I Q from five .to twelve carbon atoms, are particularly advantageous for use in relatively strongly alkaline aqueous media such as mercerizing baths. Furthermore, we have found that by employing mercerizing liquidscontaining soluble salts of the lower aliphaticacids, the wetting and penetrating power of the bath is so great that the boiling out or purification process may be eliminated. In other words by employing mercerizing liquids in accordance with our-invention 10 unboiled or grey cotton may be mercerized directly, thereby saving the expense and trouble formerly involved in the purification prior to mercerization.

In practise, it has beeniou'nd that the Wetting, 15 penetrating and dispersing efiiciencies of relatively concentrated alkaline baths produced in accordance with the invention are better when the salts of the lower aliphatic carboxylic acids contained therein have branched chain rather 20 than straight chain carbon linkages.

The method employed in testing the efliciency of the products of the invention was empirical andthe results obtained were relative rather than absolute but nevertheless of such character as to 25 show the success of the invention. 1

The testing apparatus employed consisted of a glass cylinder, two inches in diameter by twenty inches in height, marked vertically in divisions of one-eighth inches each. In making the tests 30 this cylinder was filled with mercerizing liquids containing various addition agents. Skeins of two-ply unboiled cotton yarns were suspended in the mercerizing liquids from a small wire hook attached to a. rod which rested on the top of the 35 glass cylinder. In each test a 25 gram weight was attached to the bottom of the skein by means of another wire hook. All of the skeins used were of exactly the same length so that the total length I of the apparatus from the rod at the top to the 40 bottom of the weight was the same in all tests. .The length of the skeins and wireswas such that the bottom of the weight was'aboutan inch above the bottom of the cylinder. a

. since shrinkage of the cotton fiber being mer- 5 cerized is one of the characteristics of the mercerization process, the ratefof shrinkage .of the skein was measured. This was done by, dropping the skein with weight attached into a givenmercerizing liquor, and simultaneously starting a 50 stop watch. The time required for a definite shrinkage (1% inches) was measured by noting the time at which the weight had risen to a predetermined mark. The time required in each case was therefore a measure of the relative efll- 55 V ciency of the mercerizing bath. Forpurposes of comparison, tests were made with a mercerizing liquor containing no penetrating agent and also with mercerizing liquors containing one of the typical preparations now in use. The temperagenation of carbon oxides disclosed in a U. S. patent to Roger Williams, No. 1,820,417. The approximate composition of these fractions and the addition agents obtained therefrom are set forth in Table II following:

Table II Boiling Approximate Boiling ints or composition Chief components Addition agent range of Components p0 oi dehydrogenfraction C. gdf 5% ated products.

A 150-160 2 4 dimethyl 159.5 65:1: Sodium salt of 1 pentanol-l. 3 dimethylvalenc acid. Secondary 8100 35:1:

hols.

B 160-170 4 methyl -hexa 165. 0 40:1: Sodium salts of nol-l. 3 moth 2 4 dimethyl 171.0 25:1: caproic ecid and hexanol-l. l 3- dimethyl capxolc acid. Secondary alco- 35:1:

hols.

C 160-190 4 methyl hex 165.0 40:1: Sodium salts of anol-l. 3 methyl ca- 2 4- dimethyl 171.0 15:1: proic acid, l -3- hexanold. dimethyl caproic +4 methyl -hep- 181.5 5:1: acid and 3 tanol-l. methyl caprylic Secondary alco- 40:l: acid.

hols.

.I) 140-150 2 methyl pent- 147.0 65$ Sodium salts anol-l. 1 methyl and 4 methyl pent 146.5 3-methylvaieric anal-1. acid. Secondary alco 35:1:

hols.

* Including small amounts of primary alcohols.

+ Identification not conclusive.

Table I Memerizing bath consisting of a Concentra- 25% solution tion 0! M eroeriza- Test No. of sodium addition tion time hydroxide agent in (seconds) containing gJliter as an addition agent Above 1 In the foregoing table, addition agents, A, B, C and D are sodium salts of lower aliphatic carboxylic acids prepared by the caustic dehydrogenation of various fractions of synthetic alcohols at a'temperature of the order of about 300 C. and a pressure of the order of about 100 atmospheres, as described in a U. S. Patent 1,856,263 to E. E. Reid. The various fractions of synthetic alcohols'employed were such as may be produced in accordance with the process for the hydro- In the process of dehydrogenation the only alcohols converted to salts of carboxylic acids are the primary alcohols, the secondary alcohols or derivatives thereof being separated from the reaction products. The various addition products therefore most probably consist substantially of the salts listed in the last column of Table 11.

The addition agent E employed in Tests Nos. 6 and 7 consisted of a mixture of 95 parts of pale cresylic acid and 5 parts of benzyl alcohol.

ferior to salts of lower aliphatic carboxylic acids of the character described. v

It will be understood that the above tests are illustrative only and do not limit the invention as to the specific salts and proportions thereof employed or as to the character of the alkaline media in which they are used; The results obtained have demonstrated that the salts of the branch chain aliphatic carboxylic acids containing 7 to 8 carbon atoms are superior to the other addition agents tested. The inclusion in mercerizing baths of salts of acids containing less than five carbon atoms has no appreciable effect upon the wetting and penetrating action of the bath. Thus, sodium butyrate is of practically no value from this standpoint. Acetates may serve to protect fibers other than cotton from the action of alkali but they have no appreciable effect upon the penetrating power of the bath. On the other hand, the salts of higher aliphatic carboxylic acids such as sodium oleate, sodium stearate and the like are of practically no value because of their insolubility. In general, we have found that the results obtained are especially advantageous with alkaline aqueous media containing soluble salts of aliphatic carboxylic acids having about 6 to 10. carbon atoms.

The comparative results clearly show that it is far in- As previously indicated, the lower aliphatic carboxylic acid salts may be added to the alkaline "media as such, or formed therein, for example,

by the addition of the free acids (seeTest 5 in Table I) or derivatives thereof which will readily decompose to give salts in the strongly alkaline bath such as, for example, amides, chlorides or anhydrides of the acids in question. In general, it is preferable to make the addition in the form of the dry alkali metal salts, or concentrated aqueous solutions thereof. In mercerizing processes, the mercerization bath generally becomes more dilute as the mercerization proceeds. It is customary in such cases to maintainthe concentration of the bath by the addition of relatively strong alkali metal' hydroxide solutions. According to the present invention the addition agents herein described can be included directly in such solutions. Instead of being employed for replenishing the bath, concentrated solutions of this character may be used in the initial preparation of the bath since they only, require dilution to the proper concentration.

The proportions of addition agent introduced into a given alkaline medium may vary within relatively wide limits depending largely upon the concentration of the alkaline reacting agent and the purpose for which the resultant product.

is to be employed. Thus, in the treatment of cotton fibers with mercerizing liquors the amount of addition agent employed will depend largely upon the degree of cleanliness of the fiber treated, the alkali concentration, the temperature of the bath, the count of the fabric (if in fabric' form) and the rapidity of mercerization which it is desired to obtain. In general, however, larger amounts will be required with more greasy materials, with more tightly woven goods and with more dilute alkaline solutions' As a general rule, about 0.5-20.0 parts of addition'agent of animal or vegetable origin, e. g., wool, silk,

cotton, ramie, jute, hemp, flax, rayon, and the like. The benefits obtained, however, even with comparatively large amounts of addition agent ,less marked in relatively giilute alkaline solutions than in thcne which are relatively concentrated. For this reason the results obtained have been especially desirable in processes involving the use of relatively concentrated alkaline baths, more particularly in the treatment of vegetable-fibers since, as is well known, animal fibers may be destroyed by the action of strong alkalies while vegetable fibers such as cellulose are less susceptible to this action.- Generally speaking, the best results are obtained in the use of alkaline baths of the character herein described containing about by weight, or more, of an alkaline reacting agent such as, for example, sodium or potassium hydroxide. In.

practise, it has been found that the eflicacy of" the addition agent is particularly marked in such alkaline baths when the alkaline-reacting agent is an alkali metal hydroxide. It will be apparent that, if desired, the bath may contain more than one alkaline reacting agent. maximum desirable concentration of the alkaline reacting substances may vary within relatively mercerized directly. sity of a preliminary boiling out and drying The.

wide depending upon the specific alkaline reacting substances, the addition agents, and the uses to which the resultant product is put. In" the case of alkali metal hydroxide mercerizing baths the concentration should preferably not greatly exceed 30%. For other purposes, it may be desirable to employ larger proportions of the alkaline reacting agent. Thus, as previously indicated, concentrated stock preparations suitable for preparing or replenishing mercerizing liquids or other alkaline aqueous mediamay be produced. Since the diiferent addition agents are stable to all concentrations of the various alkaline reacting agents, such preparations may be in any desirable form such as, for example, in paste form or in the form of concentrated aqueous solutions which may or may not contain an excess of the alkaline reacting substance or'addition agent over that required for saturation.

It will be understood that alkaline aqueous media prepared in accordance with this invention maybe employed in admixture with a wide variety of additional substances. As examples of such additional substances may be mentioned materials which possess or induce washing, cleansing, emulsifying, wetting, dispersing, adsorbing, lathering, or bleaching properties such as, for example, phenol and its homologues, benzyl alcohol, butyl and amyl alcohols, the higher synthetic alcohols (B. P. above about 120 C.) obtained by the hydrogenation of carbon oxides (see also Table II above), the Turkey red oils, aliphatic and aromatic sulfonic acids, such as alkylated naphthalene sulfonic acids, sulfonated derivatives of abietic acid, sulfuric esters, saponin, and aliphatic and aromatic. acid amides, such as sodium taurocholate or sodium salts of analogous acid amides, sodium perborate, heterocyclic bases, and pine oil.

, The principal advantage of the invention lies in the high wetting and penetrating efficiency of the products. Heretofore considerable difiiculty has been encountered in the -mercerization process because of the inefliciency of the removal of wax and grease from the fiber and resultant non-uniform 'mercerization. As a result when the fiber was dyed thedyeing was spotty and off-color where removal of wax from the fiber was incomplete or the mercerization was nonuniform. By the application of the present invention more uniform mercerization and hence vmorev even dyeing can-beobtained been The practise of the invention leads also to a more rapid mercerization thereby effecting a greater economy of time than has been possible according to the prior art. Another advantage is that, due to the great effectiveness of the products of the invention, grey cotton can be This eliminates the neceswhich has heretofore been the customary practise in the art in. order to obtain uniform mercerization.

As many apparent and widely different embodiments of this invention may be made without departing from the spirit thereof, it is to be understood that we do not limit ourselves .to the foregoing examples or description except as indicated in the following claims.

We claim:

1. An alkaline medium of improved wetting, penetrating, and dispersing power, comprising an alkaline reacting substance, water and a soluble salt of *an aliphatic carboxylic acid having 5 to 12 carbon atoms,'the alkalinity of said medium being of mercerizing strength.

2. An alkaline bath for the treatment of vegetable fibers containing in aqueous solution, an alkaline reacting substance, and a mixture of soluble salts of aliphatic carboxylic acids having 5 to 12 carbon atoms, the alkalinity of said medium being of mercerizing strength.

3. In processes involving the use of alkaline aqueous solutions of mercerizing strength, the

step which comprises improving the wetting,

penetrating and dispersing power of said solutions by including therewith a mixture of soluble salts of aliphatic carboxylic'acids having 5 to 12 carbon atoms.

aqueous solution ofsodium hydroxide oi mer- 15 cerizing strength containing sodium laurate.

W FREDERICK B. DOWNING. RICHARD G. CLARKSON. 

